Search PubMed⌕ Search

Biomedical subjects

P Bobek

Publications and source records attributed to P Bobek.

At least 55 records · Page 3Linked to original sources
PubMed1991

Effect of oyster fungus (Pleurotus ostreatus) on serum and liver lipids of Syrian hamsters with a chronic alcohol intake.

The authors studied the effect of oyster fungus (Pleurotus ostreatus) (2% dried fruiting bodies in a standard diet) on the serum and liver lipids of growing male Syrian hamsters with a chronic alcohol intake (a 15% aqueous solution). After eight weeks' alcohol intake there was an increase in their serum cholesterol, triacylglycerol (TG) and phospholipid (PL) concentration, 40 - 60% of which was accounted for by an increase in the very low density lipoprotein (VLDL) concentration. The proportion of VLDL in the lipoprotein pool rose by almost 15%, whereas the proportion of high density lipoproteins (HDL) fell. The simultaneous administration of the fungus in the diet reduced the cholesterol level below the value in the control animals not given any alcohol. Both the serum TG and the VLDL concentration fell by 30%, but neither the chemical composition and concentration of the HDL nor the cholesterol concentration were affected. The addition of the fungus to the diet completely abolished the increase induced in the liver cholesterol and TG concentration by the chronic intake of alcohol.

Alcoholism↗
PubMed1990

Effect of dehydrated apple products on the serum and liver lipids in Syrian hamsters.

The effect of two dehydrated apple products (10% in diet)--apple pulp (crude fibre 3.5%, pectin 1.4%) and apple pomaces (crude fibre 13.5%, pectin 7%)--on the serum and liver lipids of growing Syrian male hamsters were studied. The animals were fed a natural diet (38% of energy substituted by milk fat; the diet contains 53 mg of cholesterol (CH) per 100 g) which resulted in an accumulation of CH and triacylglycerols (TG) in the serum as well as in the liver, and CH-rich very low density lipoproteins (VLDL) in the circulation. After two months both apple products decreased the levels of CH and TG in serum (by 40-70%) and the content of CH in VLDL with similar efficiency. Both products reduced CH content in the liver, and the apple pulp also decreased TG content. Up to the 6th month the apple pulp studied suppresses accumulation of CH and TG in both the serum and the liver. A complete analysis of lipoproteins of main density class at the time showed that the decrease of serum CH and TG to a decisive extent is due to the decrease of their concentration in VLDL (by more than 50%). Therefore, the concentration of VLDL and the whole lipoprotein pool decreased by 50%. The apple pulp doubled the amount of CH transported by HDL. Three months after the replacement of butter in the diet by corn germ oil the CH and TG levels in the serum and TG also in the liver decreased to the physiological level.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Long-term hypolipaemic effect of apple pulp on golden hamsters with alimentary hyperlipoproteinaemia.

Golden hamsters with alimentary hyperlipoproteinaemia (fed on a diet in which 44% of the energy was accounted for by fats, 52 mg cholesterol (CH)/100 g) were given apple pulp (10% of the diet) for six months. From the end of the first month up to the end of the experiment, elevation of serum CH, triacylglycerol (TG) and phospholipid (PL) levels and CH and TG accumulation in the liver were effectively inhibited. At the close of the experiment, hyperlipoproteinaemia was characterized by an increase in the amount of very low density lipoproteins (VLDL), which carried 60-80% of all circulating lipids, accounted for over 70% of the total lipoprotein pool and transported almost 60% of the serum CH (high density lipoproteins--HDL--only 16%). The apple diet markedly reduced (by 50-80%) the amount of all lipids in the lipoproteins within density limits of 1,006-1,063 kg/m3 and lowered the total lipid concentration in these density classes and in the lipoprotein pool as a whole (by 50%). The proportion of the individual lipoprotein classes in the lipoprotein pool was not significantly affected. The apple diet did not affect either the chemical composition of HDL or their participation in the lipoprotein pool, but raised the proportion of serum CH transported in this lipoprotein class. Neither the lipoprotein lipase activity of the adipose tissue nor lecithin:cholesterol acyltransferase activity were influenced by the apple diet.

Adipose Tissue↗
PubMed1984

Effect of pectin on cholesterol distribution in the lipoproteins of streptozotocin-diabetic rats fed cholesterol diet.

In rats fed a semisynthetic diet, streptozotocin-induced diabetes [45 mg/kg, 17 days] led to hypertriglyceridaemia [6.4 mmol/l], to a marked increase in the proportion of plasma cholesterol present in the very low density lipoproteins [VLDL] [to 40 %] and to a decrease in the amount present in the high density lipoproteins [HDL] [to 34 %]. The addition of 0.25 % cholesterol to the above diet led in healthy rats to hypercholesterolaemia [4.3 mmol/l] and to similar changes in the distribution of cholesterol in the lipoproteins. In diabetic rats, the same diet led to pronounced hypertriglyceridaemia [13.8 mmol/l] and hypercholesterolaemia [18.9 mmol/l], while the proportion of HDL-borne plasma cholesterol fell still further to 6 % and rose in the VLDL to 70 %. The addition of pectin to the diet in 6 % concentration markedly inhibited triglyceridaemia [3.3 mmol/l] and cholesterolaemia [4.4 mmol/l] and raised the proportion of HDL plasma cholesterol to 47 %.

Animals↗
PubMed1982

Vitamin C in the control of hypercholesterolemia in man.

The activity of the cholesterol 7 alpha-hydroxylating system containing cyto-chrome P-450 is depressed in the liver of guinea-pigs with chronic marginal vitamin C deficiency. Slowing-down of this rate-limiting reaction of cholesterol transformation to bile acids causes cholesterol accumulation in the liver, blood plasma and arteries, increase in the index total: HDL cholesterol, prolongation of plasma cholesterol half-life, increase in the index cholesterol: bile acids in the gall-bladder bile, cholesterol gallstone formation and atheromatous changes on coronary arteries in guinea-pigs with long-lasting marginal vitamin C deficiency. The most effective means for preventing these changes are vitamin C doses ensuring maximal steady-state levels of ascorbate in the tissues. In most of hypercholesterolemic persons with a low vitamin C status, the administration of ascorbic acid in doses 500-1000 mg per day lowers total cholesterol concentration in blood plasma. This effect may be reinforced through a simultaneous administration of bile acids sequestrants, such as cholestyramine or pectin. In every form of hypercholesterolemia therapy (dietary and/or pharmacological), an adequate vitamin C supply should be ensured in doses capable of creating maximal steady-state levels of ascorbate in human tissues.

Ascorbic Acid↗
PubMed1981

Kinetics of plasma triglycerides in rats with streptozotocin diabetes.

Streptozotocin diabetes [45 mg/kg] in rats fed on a standard diet, with insulin substitutional therapy - 66 [nkat/kg]/d [[4 U/kg b.w.]d] for the first 3 days - led during an 8 days' experiment to marked hypertriglyceridaemia [4.86 mmol/l] and to triglyceride accumulation in the liver [22.35 mmol/kg]. The endogenous triglyceride secretion rate, studied by means of a Triton WR 1339 block of lipoprotein lipase, was almost 30 % lower in diabetic rats. The half-time of plasma 14C-triglycerides [labelled endogenously with 14C-1-palmitic acid] almost doubled and the fractional turnover rate fell to half the value in the control animals. Hypertriglyceridaemia in diabetic rats [60 % insulin deficiency] is caused by slower removal of lipoprotein triglycerides from the plasma space, owing to reduced lipolytic activity in the peripheral tissues.

Animals↗
PubMed1980

The effect of chronic marginal vitamin C deficiency on the rate of secretion and the removal of plasma triglycerides in guinea-pigs.

In guinea-pigs, chronic borderline vitamin C deficiency leads to hypertriglyceridaemia and to the accumulation of triglycerides in the liver. We investigated the triglyceride secretion rate by determining the rate of accumulation of triglycerides in the plasma following a Triton WR 1339 block of the their removal from the plasma (experiment 1) and the rate of the removal of triglycerides from the plasma by mathematical analysis of the specific plasma triglyceride activity - time curve after the administration of 3H-glycerol (experiment 2). In the 14th and 16th week of the experiment it was found that borderline vitamin C deficiency slowed down the triglyceride secretion rate, prolonged the half-time and reduced fractional plasma triglyceride turnover. The balance shift between the rate of the uptake and removal of very low density lipoprotein triglycerides (VLDL-TG) in the plasma compartment (greater retardation of the catabolic phase of kinetics) is probably the reason why triglycerides accumulate in the plasma and liver compartment of guinea-pigs with borderline vitamin C deficiency.

Animals↗
PubMed1979

Tissue levels and optimum dosage of vitamin C in guinea pigs.

Ascorbic acid mixed with the diet of guinea pigs achieved substantially higher maximum tissue concentrations of ascorbate than when ascorbic acid was administered orally once a day. A 0.5% w/w of ascorbic acid in the diet ensured a state close to maximal tissue steady-state levels of ascorbate. In guinea pigs fed a diet with a high content of saturated fatty acids or with 0.2% w/w of cholesterol, the highest rate of cholesterol transformation into bile acids and the lowest concentration of total lipids, cholesterol and triglycerides in blood serum and liver were found in the group fed a diet with 0.5% w/w of ascorbic acid as compared to the marginal-deficiency group and the group receiving 0.05% w/w of ascorbic acid in the diet. Maximal tissue steady-state levels of vitamin C are probably optimal for the guinea pigs' health.

Animals↗
PubMed1979

Natural hypocholesterolemic agent: pectin plus ascorbic acid.

An addition of 5% citrus pectin and 0.5% ascorbic acid to high-fat diet of guinea pigs prevented total cholesterol accumulation in blood serum and the liver. Two groups of persons were given a preparation containing a daily dose of 15 g pectin and 450 mg ascorbic acid for 6 weeks. In 21 healthy persons with mild hypercholesterolemia total serum cholesterol dropped significantly by 24 mg/100 ml (8.6%), while the concentration of high density lipoprotein cholesterol remained unchanged. In 11 hyperlipemic outpatients (type IIa, IIb and IV) total serum cholesterol dropped by 68 mg/100 ml (18.7%). The changes in triglyceridemia proved inconsistent.

Animals↗
PubMed1978

Effect of infrequent feeding and increased physical activity on cholesterol kinetics in the rat.

The authors studied the effect of chronic physical exercise (running in a rotating drum at 850 m/hour, 5 times a week for 16 weeks) on the size of the cholesterol body pools and on cholesterol kinetics in adult male Wistar rats fed on a standard diet either ad libitum or 2 hours daily [33 weeks]. These data were obtained by mathematical analysis of the curve expressing the correlation of specific plasma cholesterol activity to time after a single dose of cholesterol-4-14C. Chronic physical stress and infrequent feeding, as separate experimental stimuli, both caused cholesterol to shift from the blood plasma at a higher rate and reduced the size of one or both cholesterol body pools (with quick or slow turnover, pools A and B). Physical exercise also reduced fractional cholesterol turnover in pool A. When the two stimuli were combined, i.e. in infrequently fed and chronically stressed rats, the rate of the cholesterol shift from the blood plasma slowed down, the total and irreversible shift of cholesterol from pool A diminished and the production rate in this pool also fell.

Animals↗
PubMed1978

Effect of chronic physical exercise on cholesterol biosynthesis in meal-fed rats.

Chronic physical exercise (in a rotating drum) influenced liver cholesterologenesis (from acetate-l-14C) in vivo in meal-fed rats (for 2 hours daily) in close temporary correlation with the time of realimentation. If always performed just prior to feeding physical exercise blocks the development of adaptive hyperchloesterologenesis as a metabolic response to infrequent feeding. If it is performed 3 and a half hours after realimentation, the stimulating effect of infrequent feeding on liver cholesterologenesis is not modified.

Animals↗